Embodiments of the disclosure described herein relate to a semiconductor memory, and more particularly, relate to an operation mode of a nonvolatile memory system.
A semiconductor memory device refers to a memory device that is implemented using a semiconductor such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), or indium phosphide (InP). A semiconductor memory device is roughly divided into a volatile memory device and a nonvolatile memory device.
A volatile memory device refers to a memory device which loses data stored therein at power-off. The volatile memory device includes a static random access memory (SRAM), a dynamic RAM (DRAM), and a synchronous DRAM. A nonvolatile memory device refers to a memory device which retains data stored therein even at power-off. The nonvolatile memory device includes a read only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable and programmable ROM (EEPROM), a flash memory device, a phase-change RAM (PRAM), a magnetic RAM (MRAM), a resistive RAM (ReRAM), and a ferroelectric RAM (FRAM).
A flash memory is widely used as mass storage media. Nowadays, as an interface technique is developed, a demand on the flash memory with improved performance is increasing. Moreover, when the flash memory repeats a program operation and an erase operation as many as a specific frequency, the validity of data stored therein is not guaranteed. That is, since a flash memory based storage device has a life of a specific level, various methods are being developed to improve the life of the flash memory.